One mode of the invention relates to a producing a device for chopped fiber bundles having a chopper unit including a cutting blade for cutting long fiber bundles, a guide for restricting the travel direction of the fiber bundles to be supplied to the cutting means, and a structure, provided between the chopper unit and the guide, that widens the fiber bundles. The invention also relates to method for producing chopped fiber bundles by widening fiber bundles while restricting the travel direction of the long fiber bundles to be supplied to chopper unit by a guide, and obtaining chopped fiber bundles by cutting the fiber bundles with the chopper unit.

One mode of the invention relates to a producing device for chopped fiber bundles comprising: cutting means including a cutting blade for cutting long fiber bundles, guide means for restricting the travel direction of the fiber bundles to be supplied to the cutting means, and widening means provided between the cutting means and the guide means and for widening the fiber bundles; and a producing method for chopped fiber bundles comprising: widening fiber bundles by widening means provided between a cutting means and guide means while restricting the travel direction of the long fiber bundles to be supplied to the cutting means by the guide means, and obtaining chopped fiber bundles by cutting the fiber bundles with the cutting means including a cutting blade.